a.	X.HAND		e.	X.KNEE
	b.	X.ELBOW		f.	X.ANKLE
	c.	X.SHOULDER	g.	X.FOOT
	d.	X.HIP
X = right or left depending uponwhich side of the body is being used.

15.1.3 The DELTA Main Menu   In the DELTA Main Menu, the program will give the user the following options:

	Input - is used to input parameter information for the sequence
	Display - allows viewing of the lifting positions of each frame
	Calculate - displays the calculations for back compression upper limit (BCUL) and back compression design limit (BCDL), percentage capability of each joint and the L5/S1 shear force at each frame
	Hardcopy - gives various options to print out a hardcopy of the DELTA file.
	Information - provides basic definition and explanation to understand the terminology used in the lift display.
	Quit - allows the user to leave the DELTA Program and return to the APAS Main Menu.

15.2 INPUT   Once the Input option has been selected the Input Menu will display the following choices:

	Parameters - inputs information
	Sequence - is used to select files to be analyzed
	Directory - for selection of drive and directories
	Previous - will direct the program back to the DELTA Main Menu.

It is recommended that Directory be selected first to insure that the proper drive and directory have been designated and then Sequence may be used to select the file to be analyzed.

15.2.1 Parameters   Selecting Parameters option displays the Input Parameters Screen and allows the user to change them. The various input parameters range from the analyst's name, the subject's name (first and last), and the subject's age, sex, and number. Parameters also includes information on the number of hands lifting the load (two hands), the load weight (in KG), the average frequency of lifts per minute, the duration of the lifting period in hours per day, the symmetry angle (degrees), and the coupling class.

The symmetry angle is the angular displacement of the load from the sagittal plane. This should be measured at the origin and destination of the lift (degrees). For a given weight, asymmetric lifting is more likely to induce injury than symmetric lifting and should be avoided. The coupling class is the gripping method, which can affect the force a worker uses upon an object. In general, a good coupling will reduce the force required to lift an object and increase the acceptable weight for lifting, whereas a poor coupling will increase the force required to lift an object and decrease the acceptable weight for lifting. The effectiveness of the coupling is not fixed, but may change with the altitude of the object above the ground. In other words, a "Good" coupling can quickly become "Poor" coupling during a lift. Therefore, the entire range of the lift should be considered, and determination should be based on overall effectiveness during the lift in classifying hand-to-object couplings.

Coupling is not always clear on what is "Good", "Fair", or "Poor". The Coupling Table gives a general ouline for coupling.

Changing the input parameters will cause the DELTA program to recalculate the information. After any changes have been made the program will run through the lift while calculating the new parameters. A screen will inform the user "Output is automatically calculated or recalculated whenever the input is changed. Select OK to proceed". Once the program has completed the calculations, it will return the user to the DELTA Main Menu.

15.2.2 Sequence   When Sequence is selected, the program will ask the user to select an input file from a list displayed on the monitor. The mouse or up/down arrows may be used to select the proper file. Once an input file has been designated, the program will return to the Input Menu.

15.2.3 Directory   The user must designate the exact location where the appropriate lift file can be found. The first entry is the letter designation of the drive. The second entry on the second line is for the directory name followed by a \ (backslash) and the subdirectory name (if any).

If the user selects a drive and directory that the computer cannot locate them, it will tell the user that the designated drive and directory do not exist. Click OK is selected the DELTA program will take the user back to the Input Menu.

15.3 DISPLAY   The Display option allows the user to view the lifting position at each frame and the value of each variable at that time of the lift. The Display Menu is selected from the DELTA Main Menu and presents the following choices:

	Significant Frames - aloows the user to view particular frames at their most extreme values.
	Scroll Frames - allows the user to step through each frame of the lift.
	Time Plots - displays a curve, graphing the values of each variable over the time execution of each subjects lift.
	Summary - shows the lifting report with a comparison to NIOSH standards in text form.
	Previous - returns to the DELTA Main Menu.

15.3.1 Significant Frames   Once Significant frames has been selected, the program will display a screen divided into four parts. Each part represents given information of a specific frame of the lift. The first part, the top left section of the screen, displays the percentage capability of each joint. The second part, the top right section of the screen, shows a two-dimensional view of the subject's position with the chosen extreme value. The third part, the bottom left section of the screen, displays the shear force in Newton's exerted upon the lower back (the L5/S1 joint). The fourth part, the bottom right section of the screen, will tell the user the amount of compression force exerted upon the lower back in Newton's, and whether this ranges below or between the BCDL and BCUL. Anything below the BCDL indicates a safe lift, and anything between the BCDL and BCUL indicates a potentially hazardous lift.

Also displayed at the top of the screen is the Values Menu. The menu will provide the following options, that display the frame of the lift where:

	Max_C - the amount of compression force applied to the lower back is at its most extreme value.
	Max_S - the amount of shear force applied to the lower back is at its most extreme value.
	Min_E - the elbow is at its lowest percentage capability.
	Min_S - the shoulder is at its lowest percentage capability.
	Min_T - L5-S1 is at its lowest percentage capability.
	Min_H - the hip is at its lowest percentage capability.
	Min_K - the knee is at its lowest percentage capability.
	Min_A - the ankle is at its lowest percentage capability.
	Print - allows the user to generate a hardcopy of the graphics screen currently displayed.
	Quit - returns to the Display Menu.

15.3.2 Scroll Frames   When Scroll frames a screen will be displayed, divided into four parts, just as in section 15.3.1. This gives the user the capacity to view the subject's position, the percentage of capability of each joint, the shear force in Newton's, and the BCUL and BCDL at each frame during the lift.

Also displayed at the top of the screen is the Scroll Fame Menu which provide the following options:

	Next Frame - allows the user to advance to the next frame of the lift.
	Previous Frame - allows the user to go back to the previously viewed frame of the lift.
	First Frame - allows the user to go directly to the first frame of the lift.
	Last Frame - allows the user to go directly to the last frame of the lift.
	Print - sllows the user to print out a hardcopy of the graphics screen currently displayed.
	Previous - returns to the Display Menu.

15.3.3 Time Plots   Time Plots displays a curve, graphing the values of each variable over the time execution of each subject's lift. When Time Plots is selected the program will instruct "while viewing a time plot, strike any key to return to this menu or control print screen for hardcopy. Choose a time plot."

The Time Plots Menu displays the following choices:

	Force - displays the time plot of L5/S1 forces.
	Ankle/Knee - displays the ankle and knee joint strength capability.
	Hip L5/S1 - displays the hip L5/S1 joint strength capability.
	Elbow/Shoulder - displays the elbow and shoulder joint percentage capbility
	Balance - displays a time plot for the center of gravity location relative to the foot and ankle position in centimeters.
	Previous - returns to the Display Menu.

15.3.3.1 Force   When Force is selected, the program will display two different time plots: one for the compression force in Newton's and one for the shear force in Newton's applied to the lower back. Above these two time plots, the program will display the subject's position at various frames of the lift.

The top time plot curve will display the compression force in Newton's applied to the lower back over time in seconds. This time plot curve will show whether the curve is below the Back Compression Design Limit (BCDL), or how much it ranges between the BCDL and the Back Compression Upper Limit (BCUL), or above it. This program will also pinpoint on the curve where the compression force exerted upon the lower back is at its maximum.

The bottom time plot curve will display the range in shear force in Newton's applied to the lower back over the time of the lift. Like the top time plot curve, the program will also pinpoint the frame and time of the lift in this time plot curve where the shear force applied to the lower back is at its maximum value. Since the NIOSH database doesn't offer any specific limits, there is no comparison to BCUL or BCDL.

To leave the "Force" time plot display, strike any key or click the mouse and the program will direct itself back to the Display Menu.

15.3.3.2 Ankle_Knee   The program will display for this option two time plot curves, one for the ankle and one for the knee. As with the "Force" time plot, the program will display the subject's lift position at different periods of the lift. Both time plot curves will show how the curve for each joint (representing percentage capability) changes during the lift and whether these curves dip below the Strength Design Limit (SDL), and the Strength Upper Limit (SUL), which are displayed on the curves by a blue line. The program will pinpoint the frame and time of the lift in which the subject's ankles and knees are at their minimum percentage capability. The program will also display the value of the minimum percentage capability of each joint.

To leave the "Ankle/Knee" time plot display, strike any key or click the mouse and the program will direct itself back to the Display Menu.

15.3.3.3 Hip_L5/S1   This option shows the subject's hip L5/S1's percentage capability on a time plot curve. Like section 15.3.3.2, the program will display the same type of values for the hip joint.

To leave the "Hip" time plot display, strike any key or click the mouse and the program will direct itself back to the Display Menu.

15.3.3.4 Elbow_Shoulder   This option shows the subject's elbow and shoulder joints' percentage capability on a time plot curve. Like sections 15.3.3.2 and 15.3.3.3, the program will display the same type of values for the elbow and shoulder joints.

To leave the "Elbow/Shoulder" time plot display, strike any key or click the mouse and the program will direct itself back to the Display Menu.

15.3.3.5 Balance   By selecting this option, the program will display a time plot with three different curves measuring the horizontal location of the foot, ankle, and center of gravity. Two of the curves, Foot X and Ankle X, will be marked in blue. These curves indicate the foot and ankle's position to each other. The third curve, CGX, will be marked in white. The curve CGX indicates the location of the center of gravity of the subject during the lift. It should be noted that if the CGX line rises above the foot X line, this indicates the subject may be losing balance.

To leave the "Balance" time plot display, strike any key or click the mouse and the program will direct itself back to the Display Menu.

15.3.4 Summary   Selecting the summary option will show the NIOSH Lifting Report with a comparison to NIOSH standards in text form. The summary consists of data listing the subject's name, the subject's number, and the analyst's name. The data will also list the date the study was done, the subject's height (in CM), the subject's weight (in KG), the age of the subject, the subject's sex, the number of hands used during the lift, the lift frequency (in lifts per minute), the lift duration (in hours per day), the load weight, the NIOSH action limit (AL) and the NIOSH maximum permissible limit (MPL). It should be noted that load weights at or above the MPL are considered absolutely unacceptable. Load weights between the AL and MPL are considered unacceptable without administrative or engineering controls.

The summary will also consist of the Recommended Weight Limit (RWL), and the Lifting Index (LI). The RWL is a new limit on weight lifted which is currently being proposed by NIOSH affiliated scientists. The RWL is intended to replace the AL and the MPL. The RWL is based on a multiplicative model that provides a weighting for each task variable. The weightings are expressed as coefficients that are used in the model to decrease the recommended load constant (i.e., maximum weight to be lifted). The lifting index is the load weight divided by the recommended weight limit.

The "Summary" option will also display the values for the maximum L5-S1 compression, the maximum L5-S1 shear, the minimum elbow moment % capable, the minimum shoulder moment % capable, the minimum L5-S1 moment % capable, the minimum hip moment % capable, the minimum knee moment % capable, and the minimum ankle moment % capable. This option will also display to the right of these values those that fall below the SDL, and those that are above the BCDL.

To leave the Summary option, select continue with the mouse to return to the Display menu and hard copy to print out the information.

15.4 CALCULATIONS   The Calculations Option is selected from the DELTA Main Menu and serves to display the program's calculations for BCUL and BCDL, the percentage capability of each joint, and the L5/S1 shear force at each frame of the lift. The Calculations option will also display to the user the subject's lift position at each frame of the lift.

After a file has been chosen and Calculations have been selected, the program will run the lift, frame by frame, showing the calculations. Once the lift is finished, the program will return the user back to the DELTA Main Menu.

15.5 HARDCOPY   Selecting Hardcopy from the DELTA Main Menu provides the user with various options to print out a hardcopy of the DELTA file. Once Hardcopy has been selected, the Print Menu will display the following choices:

	Report - prints out an L5/S1 Force Report.
	Frames - prints out the significant frames and the summary table.
	Plots High - print out the time plots at a high resolution, but at a slower speed.
	Plots Low - print out the time plots at a low resolution, but at a higher speed.
	All High - print out the L5/S1 force report, the significant frames, and the time plots all at a high resolution, but at a slower speed.
	All Low - print out the L5/S1 force report, the significant frames, and the time plots all at a low resolution, but at a higher speed.
	Previous - returns to the DELTA Main Menu.

15.6 INFORMATION   Selecting Information from the DELTA Main Menu provides the user with the basic definition and explanation to understand the terminology used in the lift display. The information section also provides the user with valuable knowledge of NIOSH Standards regarding compression, load, and strength limits. This data is vital to the user in order to understand when a lift is safe, potentially hazardous, and what joints are enduring the most stress. The Information Menu lists the following options:

	Compression - information about NIOSH compression limits.
	Shear - information about NIOSH shear limits.
	Old Load - information about the old (1982) NIOSH load limits.
	New Load - information about the new (1992) NIOSH load limits.
	Strength - information about NIOSH strength limits.
	Previous - returns to the DELTA Main Menu (Figure 15-1).

15.6.1 Compression   Selecting "compression" provides the user with NIOSH definition and limits on the compressive force exerted upon the sacral vertebra (L5/S1).

NIOSH has recommended that values above the BCUL (back compression upper limit) be considered hazardous to most workers. The BCUL is 6400 Newton's.

NIOSH has also recommended that values between the BCDL (back compression design limit) and the BCUL be considered potentially hazardous for some workers. The BCDL is 3400 Newton's.

At the bottom of the screen, the program will provide an OK symbol to click with the mouse once the user has finished viewing the information on compression. Selecting OK will return the user back to the Information Menu.

15.6.2 Shear   NIOSH does not currently provide limits on shear force at L5/S1. Simply click OK with the mouse to return to the Information Menu.

15.6.3 Old Load   This option shows the 1982 NIOSH standards that provide an equation which relates frequency of lift, lifting period, initial load position, and vertical travel of load to limits on the amount of mass which an individual can safely lift.

MPL is the NIOSH maximum permissible limit. Load masses above the MPL should be considered unacceptable, and engineering controls should be sought to redesign the lifting conditions.

AL is the NIOSH action limit. Loads weighing between the AL and MPL are unacceptable without administrative or engineering controls: thus requiring careful employee selection, placement and training, and/or job redesign.

Click OK with the mouse to return to the Information Menu.

15.6.4 New Load   The revised (1992) NIOSH lifting equation relates frequency of lift, lifting period, initial load position, vertical travel of load, lifting asymmetry, and hand-to-object coupling to a limit on the amount of mass which an individual can safely lift. This limit is called the recommended weight limit (RWL).

A lifting index (LI) is also defined which is the ratio of load weight to RWL.

Click OK with the mouse to return to the Information Menu.

15.6.5 Strength   In regards to strength limits, the DELTA program provides NIOSH limits on the strength required at each joint during a lift.

SUL is the strength upper limit. When the percent capacity falls below the SUL, the lift conditions should be considered unacceptable, and engineering controls should be sought to redesign the lifting conditions. The SUL IS 25% for men and 1% for women.

SDL is the strength design limit. When the percent capability falls between the SDL and SUL, the lifting conditions are unacceptable without administrative or engineering controls: thus, requiring careful employee selection, placement, training, and/or job redesign. The SDL is 99% for men and 75% for women.

Click OK with the mouse to return to the Information Menu or control print screen for a hardcopy.